Ok, so you've finally decided to it's ok to quit your program, but you're freaking out about how you will put food on the table. First, the good news is that as a graduate student you are very likely making under the federal poverty level, which means pretty much any job will pay better. I still remember when my therapist asked me what was the worst thing possible that could happen if I quit, and I answered working at Starbucks. Hello, working full-time at Starbucks provides more money and better health care than most graduate students receive, so don't worry--pretty much any job will be an improvement if it brings a pay check instead of more loans.
Second, don't underestimate the value of your graduate school training, no matter how worthless you feel your degree may be. You basically went to college twice as long as most entry level employees, and you presumably picked up some analytical writing and critical reasoning skills that should come in quite handy. At the very least your learned to bullshit your way through discussions of long, boring articles you probably didn't read, which means you will be able to handle impromptu questions from customers and bosses with ease.
Most importantly, if you ever did research or managed a research team of undergraduates, you can easily claim management experience which is more than many of the bosses I have subsequently worked for ever did. Guiding a group of people toward a common goal, ensuring everyone is coding consistently and keeping up with deadlines, facilitating research meetings, and writing up findings with a number of authors are all great resume worthy skills that you should be highlighting. Because you may not have known it, but those are all management skills that you should be pitching in interviews. While it helps to have managed paid staff, the secret is that any management, even of interns and free labor, can be considered when it comes to hiring.
I would also point out that escaped graduate students make some of the best employees. We're highly motivated, smart, but also practical enough to know when to call it quits, and generally desperate to get out there into the world and earn a paycheck. Yes, sometimes we are an arrogant bunch, and we can be bored and under stimulated in many jobs. But we write well, and quickly. We love our 9-5 schedule. but don't shrink from deadlines, or have an issue with needing to put in more time and effort. We survived harsh working conditions and miserable emotionally deadening slogs through material denser than anything you will ever encounter in the corporate world. Departmental politics are a more than adequate training ground for office politics.
For a lot of managers, the secret in hiring is escaped graduate students. And I can tell you from personal experience that a lot of the hiring managers are themselves students who bailed on the Ph.D. I always take a second look when I see a resume come across from someone that didn't finish. Because sometimes the best person for the job is a non-traditional candidate who knew when to call it quits.